As we count down to Wicked 15, Playbill discovers how these original leading ladies left indelible marks on each of their roles.

When creating an original musical, it’s common for composers and writers to cater the material to the actors performing the brand new roles. Wicked is no exception.

As it turns out, Idina Menzel asked Stephen Schwartz to change the ending of “Defying Gravity,” and not just by adding her signature riff. (Watch the full video above to find out what it was.) For Kristin Chenoweth, her lasting contribution comes more in the form of comedy than vocal pyrotechnics.

Menzel also shared what it was like to fly for the first time and more, as the ladies prepare to host A Very Wicked Halloween October 29 at 10PM ET on NBC. Tune in to the concert special to hear more behind-the-scenes stories and music from the Tony-winning musical.